A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 8773440 can be evenly divided by 1 2 3 4 5 6 8 10 12 13 15 16 19 20 24 26 30 32 37 38 39 40 48 52 57 60 64 65 74 76 78 80 95 96 104 111 114 120 130 148 152 156 160 185 190 192 195 208 222 228 240 247 260 285 296 304 312 320 370 380 390 416 444 456 480 481 494 520 555 570 592 608 624 703 740 741 760 780 832 888 912 960 962 988 1,040 1,110 1,140 1,184 1,216 1,235 1,248 1,406 1,443 1,480 1,482 1,520 1,560 1,776 1,824 1,924 1,976 2,080 2,109 2,220 2,280 2,368 2,405 2,470 2,496 2,812 2,886 2,960 2,964 3,040 3,120 3,515 3,552 3,648 3,705 3,848 3,952 4,160 4,218 4,440 4,560 4,810 4,940 5,624 5,772 5,920 5,928 6,080 6,240 7,030 7,104 7,215 7,410 7,696 7,904 8,436 8,880 9,120 9,139 9,620 9,880 10,545 11,248 11,544 11,840 11,856 12,480 14,060 14,430 14,820 15,392 15,808 16,872 17,760 18,240 18,278 19,240 19,760 21,090 22,496 23,088 23,712 27,417 28,120 28,860 29,640 30,784 33,744 35,520 36,556 38,480 39,520 42,180 44,992 45,695 46,176 47,424 54,834 56,240 57,720 59,280 67,488 73,112 76,960 79,040 84,360 91,390 92,352 109,668 112,480 115,440 118,560 134,976 137,085 146,224 153,920 168,720 182,780 219,336 224,960 230,880 237,120 274,170 292,448 337,440 365,560 438,672 461,760 548,340 584,896 674,880 731,120 877,344 1,096,680 1,462,240 1,754,688 2,193,360 2,924,480 4,386,720 and 8,773,440, with no remainder.
Since 8,773,440 cannot be divided by just 1 and 8,773,440, it is not a prime number.